Regular triangle where T(n,k) is the number of pairs of set partitions of {1,...,n} with join {{1,...,n}} and meet of length k.
A318390
Regular triangle where T(n,k) is the number of pairs of set partitions of {1,...,n} with join {{1,...,n}} and meet of length k.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =6a(5) =8a(6) =1a(7) =14a(8) =48a(9) =56a(10) =1a(11) =30a(12) =200a(13) =560a(14) =552a(15) =1a(16) =62a(17) =720a(18) =3640a(19) =8280a(20) =7202a(21) =1a(22) =126a(23) =2408a(24) =19600a(25) =77280a(26) =151242a(27) =118456a(28) =1a(29) =254
External references
- oeis: A318390